Southwest airlines boosted one-way ticket prices on many of its Florida routes by $10 on Friday. The increases are affecting 16% of the airline's markets.

Delta and American followed with a similar hike on the Florida routes where they compete with Southwest, said Rick Seaney of price-tracking site FareCompare.com.

US Airways also bumped up one-fares by $10, but on a larger swath of its domestic network.

If this latest attempt to boost domestic fares sticks, it would be the eighth successful increase of the year, Seaney said. Airlines have now tried 15 times to bump up the price for a ticket on a domestic flight. Last year, there were 22 attempts, and nine succeeded.

"Bottom line - a hike is underway,'' Seaney said, adding that the full scope remains to be seen.

Southwest usually sets the pace when it comes to fare increases, since most other airlines don't want to stand out by charging more than the carrier, which flies more domestic passengers than any of its peers.

Southwest's latest hike was "due to the continued cost increase of doing business, '' said Southwest spokeswoman Katie McDonald.

Airlines have pointed to fluctuating fuel costs as a key reason for raising fares. And they have more power to do it, after winnowing the number of seats and flights available for those who want to fly.